xref: /linux/drivers/nvme/host/pr.c (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2015 Intel Corporation
4  *	Keith Busch <kbusch@kernel.org>
5  */
6 #include <linux/blkdev.h>
7 #include <linux/pr.h>
8 #include <asm/unaligned.h>
9 
10 #include "nvme.h"
11 
12 static enum nvme_pr_type nvme_pr_type_from_blk(enum pr_type type)
13 {
14 	switch (type) {
15 	case PR_WRITE_EXCLUSIVE:
16 		return NVME_PR_WRITE_EXCLUSIVE;
17 	case PR_EXCLUSIVE_ACCESS:
18 		return NVME_PR_EXCLUSIVE_ACCESS;
19 	case PR_WRITE_EXCLUSIVE_REG_ONLY:
20 		return NVME_PR_WRITE_EXCLUSIVE_REG_ONLY;
21 	case PR_EXCLUSIVE_ACCESS_REG_ONLY:
22 		return NVME_PR_EXCLUSIVE_ACCESS_REG_ONLY;
23 	case PR_WRITE_EXCLUSIVE_ALL_REGS:
24 		return NVME_PR_WRITE_EXCLUSIVE_ALL_REGS;
25 	case PR_EXCLUSIVE_ACCESS_ALL_REGS:
26 		return NVME_PR_EXCLUSIVE_ACCESS_ALL_REGS;
27 	}
28 
29 	return 0;
30 }
31 
32 static enum pr_type block_pr_type_from_nvme(enum nvme_pr_type type)
33 {
34 	switch (type) {
35 	case NVME_PR_WRITE_EXCLUSIVE:
36 		return PR_WRITE_EXCLUSIVE;
37 	case NVME_PR_EXCLUSIVE_ACCESS:
38 		return PR_EXCLUSIVE_ACCESS;
39 	case NVME_PR_WRITE_EXCLUSIVE_REG_ONLY:
40 		return PR_WRITE_EXCLUSIVE_REG_ONLY;
41 	case NVME_PR_EXCLUSIVE_ACCESS_REG_ONLY:
42 		return PR_EXCLUSIVE_ACCESS_REG_ONLY;
43 	case NVME_PR_WRITE_EXCLUSIVE_ALL_REGS:
44 		return PR_WRITE_EXCLUSIVE_ALL_REGS;
45 	case NVME_PR_EXCLUSIVE_ACCESS_ALL_REGS:
46 		return PR_EXCLUSIVE_ACCESS_ALL_REGS;
47 	}
48 
49 	return 0;
50 }
51 
52 static int nvme_send_ns_head_pr_command(struct block_device *bdev,
53 		struct nvme_command *c, void *data, unsigned int data_len)
54 {
55 	struct nvme_ns_head *head = bdev->bd_disk->private_data;
56 	int srcu_idx = srcu_read_lock(&head->srcu);
57 	struct nvme_ns *ns = nvme_find_path(head);
58 	int ret = -EWOULDBLOCK;
59 
60 	if (ns) {
61 		c->common.nsid = cpu_to_le32(ns->head->ns_id);
62 		ret = nvme_submit_sync_cmd(ns->queue, c, data, data_len);
63 	}
64 	srcu_read_unlock(&head->srcu, srcu_idx);
65 	return ret;
66 }
67 
68 static int nvme_send_ns_pr_command(struct nvme_ns *ns, struct nvme_command *c,
69 		void *data, unsigned int data_len)
70 {
71 	c->common.nsid = cpu_to_le32(ns->head->ns_id);
72 	return nvme_submit_sync_cmd(ns->queue, c, data, data_len);
73 }
74 
75 static int nvme_status_to_pr_err(int status)
76 {
77 	if (nvme_is_path_error(status))
78 		return PR_STS_PATH_FAILED;
79 
80 	switch (status & NVME_SCT_SC_MASK) {
81 	case NVME_SC_SUCCESS:
82 		return PR_STS_SUCCESS;
83 	case NVME_SC_RESERVATION_CONFLICT:
84 		return PR_STS_RESERVATION_CONFLICT;
85 	case NVME_SC_ONCS_NOT_SUPPORTED:
86 		return -EOPNOTSUPP;
87 	case NVME_SC_BAD_ATTRIBUTES:
88 	case NVME_SC_INVALID_OPCODE:
89 	case NVME_SC_INVALID_FIELD:
90 	case NVME_SC_INVALID_NS:
91 		return -EINVAL;
92 	default:
93 		return PR_STS_IOERR;
94 	}
95 }
96 
97 static int nvme_send_pr_command(struct block_device *bdev,
98 		struct nvme_command *c, void *data, unsigned int data_len)
99 {
100 	if (nvme_disk_is_ns_head(bdev->bd_disk))
101 		return nvme_send_ns_head_pr_command(bdev, c, data, data_len);
102 
103 	return nvme_send_ns_pr_command(bdev->bd_disk->private_data, c, data,
104 				       data_len);
105 }
106 
107 static int nvme_pr_command(struct block_device *bdev, u32 cdw10,
108 				u64 key, u64 sa_key, u8 op)
109 {
110 	struct nvme_command c = { };
111 	u8 data[16] = { 0, };
112 	int ret;
113 
114 	put_unaligned_le64(key, &data[0]);
115 	put_unaligned_le64(sa_key, &data[8]);
116 
117 	c.common.opcode = op;
118 	c.common.cdw10 = cpu_to_le32(cdw10);
119 
120 	ret = nvme_send_pr_command(bdev, &c, data, sizeof(data));
121 	if (ret < 0)
122 		return ret;
123 
124 	return nvme_status_to_pr_err(ret);
125 }
126 
127 static int nvme_pr_register(struct block_device *bdev, u64 old,
128 		u64 new, unsigned flags)
129 {
130 	u32 cdw10;
131 
132 	if (flags & ~PR_FL_IGNORE_KEY)
133 		return -EOPNOTSUPP;
134 
135 	cdw10 = old ? 2 : 0;
136 	cdw10 |= (flags & PR_FL_IGNORE_KEY) ? 1 << 3 : 0;
137 	cdw10 |= (1 << 30) | (1 << 31); /* PTPL=1 */
138 	return nvme_pr_command(bdev, cdw10, old, new, nvme_cmd_resv_register);
139 }
140 
141 static int nvme_pr_reserve(struct block_device *bdev, u64 key,
142 		enum pr_type type, unsigned flags)
143 {
144 	u32 cdw10;
145 
146 	if (flags & ~PR_FL_IGNORE_KEY)
147 		return -EOPNOTSUPP;
148 
149 	cdw10 = nvme_pr_type_from_blk(type) << 8;
150 	cdw10 |= ((flags & PR_FL_IGNORE_KEY) ? 1 << 3 : 0);
151 	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_acquire);
152 }
153 
154 static int nvme_pr_preempt(struct block_device *bdev, u64 old, u64 new,
155 		enum pr_type type, bool abort)
156 {
157 	u32 cdw10 = nvme_pr_type_from_blk(type) << 8 | (abort ? 2 : 1);
158 
159 	return nvme_pr_command(bdev, cdw10, old, new, nvme_cmd_resv_acquire);
160 }
161 
162 static int nvme_pr_clear(struct block_device *bdev, u64 key)
163 {
164 	u32 cdw10 = 1 | (key ? 0 : 1 << 3);
165 
166 	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_release);
167 }
168 
169 static int nvme_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
170 {
171 	u32 cdw10 = nvme_pr_type_from_blk(type) << 8 | (key ? 0 : 1 << 3);
172 
173 	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_release);
174 }
175 
176 static int nvme_pr_resv_report(struct block_device *bdev, void *data,
177 		u32 data_len, bool *eds)
178 {
179 	struct nvme_command c = { };
180 	int ret;
181 
182 	c.common.opcode = nvme_cmd_resv_report;
183 	c.common.cdw10 = cpu_to_le32(nvme_bytes_to_numd(data_len));
184 	c.common.cdw11 = cpu_to_le32(NVME_EXTENDED_DATA_STRUCT);
185 	*eds = true;
186 
187 retry:
188 	ret = nvme_send_pr_command(bdev, &c, data, data_len);
189 	if (ret == NVME_SC_HOST_ID_INCONSIST &&
190 	    c.common.cdw11 == cpu_to_le32(NVME_EXTENDED_DATA_STRUCT)) {
191 		c.common.cdw11 = 0;
192 		*eds = false;
193 		goto retry;
194 	}
195 
196 	if (ret < 0)
197 		return ret;
198 
199 	return nvme_status_to_pr_err(ret);
200 }
201 
202 static int nvme_pr_read_keys(struct block_device *bdev,
203 		struct pr_keys *keys_info)
204 {
205 	u32 rse_len, num_keys = keys_info->num_keys;
206 	struct nvme_reservation_status_ext *rse;
207 	int ret, i;
208 	bool eds;
209 
210 	/*
211 	 * Assume we are using 128-bit host IDs and allocate a buffer large
212 	 * enough to get enough keys to fill the return keys buffer.
213 	 */
214 	rse_len = struct_size(rse, regctl_eds, num_keys);
215 	rse = kzalloc(rse_len, GFP_KERNEL);
216 	if (!rse)
217 		return -ENOMEM;
218 
219 	ret = nvme_pr_resv_report(bdev, rse, rse_len, &eds);
220 	if (ret)
221 		goto free_rse;
222 
223 	keys_info->generation = le32_to_cpu(rse->gen);
224 	keys_info->num_keys = get_unaligned_le16(&rse->regctl);
225 
226 	num_keys = min(num_keys, keys_info->num_keys);
227 	for (i = 0; i < num_keys; i++) {
228 		if (eds) {
229 			keys_info->keys[i] =
230 					le64_to_cpu(rse->regctl_eds[i].rkey);
231 		} else {
232 			struct nvme_reservation_status *rs;
233 
234 			rs = (struct nvme_reservation_status *)rse;
235 			keys_info->keys[i] = le64_to_cpu(rs->regctl_ds[i].rkey);
236 		}
237 	}
238 
239 free_rse:
240 	kfree(rse);
241 	return ret;
242 }
243 
244 static int nvme_pr_read_reservation(struct block_device *bdev,
245 		struct pr_held_reservation *resv)
246 {
247 	struct nvme_reservation_status_ext tmp_rse, *rse;
248 	int ret, i, num_regs;
249 	u32 rse_len;
250 	bool eds;
251 
252 get_num_regs:
253 	/*
254 	 * Get the number of registrations so we know how big to allocate
255 	 * the response buffer.
256 	 */
257 	ret = nvme_pr_resv_report(bdev, &tmp_rse, sizeof(tmp_rse), &eds);
258 	if (ret)
259 		return ret;
260 
261 	num_regs = get_unaligned_le16(&tmp_rse.regctl);
262 	if (!num_regs) {
263 		resv->generation = le32_to_cpu(tmp_rse.gen);
264 		return 0;
265 	}
266 
267 	rse_len = struct_size(rse, regctl_eds, num_regs);
268 	rse = kzalloc(rse_len, GFP_KERNEL);
269 	if (!rse)
270 		return -ENOMEM;
271 
272 	ret = nvme_pr_resv_report(bdev, rse, rse_len, &eds);
273 	if (ret)
274 		goto free_rse;
275 
276 	if (num_regs != get_unaligned_le16(&rse->regctl)) {
277 		kfree(rse);
278 		goto get_num_regs;
279 	}
280 
281 	resv->generation = le32_to_cpu(rse->gen);
282 	resv->type = block_pr_type_from_nvme(rse->rtype);
283 
284 	for (i = 0; i < num_regs; i++) {
285 		if (eds) {
286 			if (rse->regctl_eds[i].rcsts) {
287 				resv->key = le64_to_cpu(rse->regctl_eds[i].rkey);
288 				break;
289 			}
290 		} else {
291 			struct nvme_reservation_status *rs;
292 
293 			rs = (struct nvme_reservation_status *)rse;
294 			if (rs->regctl_ds[i].rcsts) {
295 				resv->key = le64_to_cpu(rs->regctl_ds[i].rkey);
296 				break;
297 			}
298 		}
299 	}
300 
301 free_rse:
302 	kfree(rse);
303 	return ret;
304 }
305 
306 const struct pr_ops nvme_pr_ops = {
307 	.pr_register	= nvme_pr_register,
308 	.pr_reserve	= nvme_pr_reserve,
309 	.pr_release	= nvme_pr_release,
310 	.pr_preempt	= nvme_pr_preempt,
311 	.pr_clear	= nvme_pr_clear,
312 	.pr_read_keys	= nvme_pr_read_keys,
313 	.pr_read_reservation = nvme_pr_read_reservation,
314 };
315